Hanna Instruments HI 84431 - Manual (Page 21)

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• After the second calibration point has been confirmed, press ESC to exit without performing
the third calibration point.
Point 3 calibration
• Remove the electrode holder with electrodes from the top of the beaker.
• Place the third buffer solution in a beaker and place in beaker holder. Rinse the probes in a
beaker with third buffer rinsing solution.
• Place the electrode holder (with electrode) in the beaker with third buffer and secure top by
locking.
• The (unstable measurement) symbol will be shown on the display until the reading
becomes stable.
• When the reading is stable and close to the selected buffer, the (unstable measurement)
symbol will disappear and the Confirm key will become active.
• Press Confirm to confirm the calibration. The instrument stores the calibration value and
returns to pH meter/titrator calibration menu, where the date and time for the last pH
calibration will be updated.
Notes:• A buffer confirmed during the calibration process is removed from the list of calibration
buffers available for further calibration points.
• If the value measured by the instrument is not close to the selected buffer a “Wrong
Buffer” error message will be shown on the display.
Check if the correct buffer has been used or regenerate the pH electrodes by following
the Cleaning Procedure (see the “pH Cleaning Procedure” section). If necessary
change the buffer or the electrode.